Preheat the oven to 450°F. Line a rimmed baking sheet with high-heat-resistant parchment paper (or foil) and spray it with avocado oil spray.
To prepare the chipotle dipping sauce, combine the mayonnaise, sour cream, and hot pepper sauce in a small bowl. Set aside.
Cut the chicken breasts into nugget-sized pieces, as shown in the video below.
In a small bowl, whisk together the egg, kosher salt, black pepper, garlic powder, and cayenne pepper.
Place the almond flour in another small bowl.
Dip each piece of chicken in the egg mixture, then dredge in the almond flour, pressing to coat. To avoid a sticky mess, use one hand to dip in the egg and the second hand to dredge in the almond flour.
Arrange the chicken nuggets in a single layer on the prepared baking sheet. Spray them with avocado oil. Bake until the bottom is golden, about 8 minutes.
Carefully flip, spray with more oil, and bake until golden and cooked through (their internal temperature should reach 165ºF), about 8 more minutes.
To promote browning, if your baking dish is broiler-safe, you can finish by broiling the chicken nuggets, in the middle of the oven, for 2-3 minutes.
Serve immediately with the chipotle dipping sauce.
Video
Notes
You won't use all the almond flour. You'll only use about half. But you need all of it to properly dredge the chicken pieces. The nutrition info reflects that.
Variation: Instead of the egg mixture, mix ¼ cup of mayonnaise with the same spices, then coat the chicken pieces with that before dredging in the almond flour.
You can keep the leftovers in the fridge, in an airtight container, for 3-4 days. Reheat them in the microwave at 50% power or in a 300°F oven. The almond flour coating is a bit fragile, so be careful when handling the nuggets. I don't recommend freezing these chicken nuggets.